A glow discharge starter is usually connected across or in parallel with an arc discharge lamp and includes a glow bottle containing a pair of electrodes. At least one of the electrodes comprises a bimetallic element which, when heated as a result of the glow discharge, bends towards the other electrode. When contact is made, the glow discharge ceases causing the bimetallic element to cool and withdraw from the contacted electrode. When contact is broken, a voltage pulse induced by the induction of the ballast, appears across the opposed electrodes of the lamp thereby initiating an arc discharge within the lamp. If the lamp ignition does not occur after the first voltage pulse, the glow discharge sequence is repeated until lamp ignition occurs. A radio frequency suppressing capacitor may be connected in parallel with the glow bottle.
A known glow discharge starter switch of the type mentioned above is described, for example, in U.K. Patent Specification No. 554,225. The starter contains a second bimetal device within the glow discharge starter switch which short-circuits the path between the main electrodes when a large quantity of heat has evolved in the glow discharge starter switch. This second bimetal device complicates the known glow discharge starter switch. This applies all the more because this second bimetal device is to be proportioned in such a manner that when it is closed the current flowing therethrough must also maintain this contact closed. A further drawback of this known device is that, due to its intricacy, its reliability is rather low.
U.S. Pat. No. 3,780,327, which issued to Vervaart et al on Dec. 18, 1973, discloses a glow discharge starter having a fuse arranged in thermal contact with the tubular part of the starter. A resilient member under mechanical Pretension exerts a pulling force on the part of the fuse to be melted. As a result, the starter is rendered inoperative by the disconnection of electrical power. A drawback of this known glow discharge starter is that it is more complicated to manufacture and requires a special spring wire and low temperature solder which themselves require proper control.
U.S. Pat. No. 3,887,847, which issued to de Graaf et al on June 1, 1975, discloses a glow discharge starter which is provided with a device which creates a short circuit across the electrodes of the starter. The device consists of a pair of conductors from a capacitor which couples the electrodes of the starter and are separated by an auxiliary member consisting of an insulating material. The auxiliary member undergoes a permanent distortion at the maximum temperature limit. The disadvantage of this arrangement is that this device is more complicated to manufacture because it requires an additional step of shaping one or more of the conductors of the capacitor and/or it requires additional components, such as a spring wire or an insulating material.